Automatic compensator for traveling felt in paper making machines



Oct. 6, 1931.

w. J. TREMPE AUTOMATIC COMPENSATOR FOR TRAVELING FELT IN PAPER MAKING MACHINES Filed July 14, 1933 2 Sheets-Sheer l 0491a Ilium ape In fall! Oct. 6, 1931. w. J. TREMPE AUTOMATIC COMPENSATOR FOR TRAVELING FELT IN PAPER MAKING MACHINES Filed July 14, 1938 2 Sheets-Sheer 2 l *1 I -w F mwnu fi mfl Patented Oct. 6, 1931 WILLIAM J. TBEMPE, OF NORTH EILLEBICA, MASSACHUSETTS AUTOMATIC COMPENSATOR EOE TRAVELING FELT 1N LAPER MAKING- MACHINES 7 Application filed m 14, 1930. Serial No. 467,793.

This invention relates generally to an automatic compensator for the traveling felt in paper making machines and is adapted to automatically compensate for the expanslon 6 contraction of the traveling felt which is subject to varying degrees of moisture.

In paper making machines the length of the traveling felt is subject to considerable variation, due to the variable de rees and 10 quantities of moisture to which t e felt is subjected. The conditions contributing to the varying degrees of moisture are thevarying grades of paper, the heavier papers carrying a relatively greater amount of mo1sture, and the heat and moisture conditions to which the traveling felt is subjected at the various points in the course of travel of the felt around the various drying rollers. As the traveling felt absorbs a larger quantity of moisture, the tendency is to" contract, and asthe felt tends to dry out or to contain a small quantity of moisture, the effeet is for the traveling felt to lengthen. The

variation in the length of the traveling felt under the two extreme conditions is a considerable one, so that if an effective and suitable means is not provided to compensate for the variable length of the felt, in order to maintain a relative uniform tension of the felt,

serious difficulty is encountered in making the paper.

While it is not broadly new to provide a compensating means for the felt. the prior art devices have been open to certain objections. It is frequently necessary to replace the traveling felt or to repair the felt by stitching the same. In certain prior art devices employing a weight, in order to entirely remove the tension from the felt in order to 40 permit such for example as a stitching operation, it has been found necessary to entirely remove the relatively heavy weights which were relied upon for maintaining tension.

Further, in devices heretofore employed a toothed rack bar and cooperating toothed gear was employed in guiding the .shiftable roller for maintaining the tension in the felt, but such construction was open to certain disadvantages one of which was the possibility of the toothed portion of the rack bar becoming clogged or filled with various foreign particles. which would interfere with the accurate and uniform functioning of the device.

One of the objects of the present invention is to provide an improved automatic compensator for the traveling felt in paper mak: ing machines, for maintaining substantially uniform tension in the traveling felt under the various degrees of moistening to which the felt is subjected.

A further object of the invention is to provide an improved automatic felt tightener which will overcome certain objections above referred to, which have been inherent in devices heretofore employed.

A further object is to provide an automatic compensator fortraveling felts in which a relatively uniform tension is maintained under normal operating conditions which tend to vary the length of the felt throughout the comparatively wide limits, andto also provide means whereby the tension may be entirely removed from the felt to facilitate replacement and repair, or to lock the tension control means imposition for any given operating condition or period, so as to render the same ineffective.

A further object is to provide in an automatic compensator for felts, in which a free hanging weight is employed for maintaining substantially uniform tension, and means to facilitate replacement or repair of the felt wherein the tension of the felt may be entirely relieved without the necessity of removing 853 or displacing the weights.

A further object is to provide in an automatic compensator for felts. an improved manually controlled 'means for selectively rendering the tension maintaining means in- 0 effective.

One preferred selected embodiment of the invention has been shown in the accompanying drawings for purposes of illustration.

The form illustrated. has been used in practical operation and has been found successful.

In the drawings:

Fig. 1 is a side elevation showing a portion only of the traveling felt and the application of the automatic compensating means thereto in order to maintain relative uniform tension of the felt under the varying conditions of expansion and contraction of the felt.

Fig. 2 is an enlarged broken section of the cage or block supporting the sheave showing the manner of adjustahly connecting ends of the sprocket chain thereto for maintaining relatively constant tension in said sprocket chain.

F ig. 3 is a fragment in section showing the relative arrangement of one end of the roller over which the felt passes together with the block and sheave.

Fig. 4 is a top plan of Fig. 1.

Fig. 5 is a diagrammatic view indicating the felt guiding roller in dot and. dash position after it has been moved, due to the contracting of the felt, and also showing the corresponding movement of the weight which maintains substantially uniform felt tension.

The automatic compensating means is mounted on the paper making machine at a suitable point in the run of the felt strip. in order to form a looped portion to provide for a substantial movement of the movable compensating roller over which the felt strip passes.

As shown, the base of the machine on which the parts are mounted, is shown as angle irons 1 which are mounted on suitable brackets 1,

forming a part of the paper making machine.

. the angle iron base 1 being spaced apart and mounted one on each side of the machine. It is understood of course, that the distance between the angle irons will vary on different machines, depending upon the width of the run of paper, in some instances the width being as great as to 12 feet.

It is important therefore that the movable compensating roller 2 over which the felt strip 3 passes. should be provided at its opposite ends with adefinite and positive control, so that in the movement of the roller to compensate for the shrinking and expansion of the felt strip under various conditions and.

degrees of moisture, aproper guide is provided for the felt, in which the axis of the roller is maintained substantially normal to the direction of travel of the felt strip thereover.

In order to provide for the accurate and proper guiding of the compensating roller 2, there is provided a pair of rails 4--5 which are supported by suitable brackets 6 on the bases, one on each side-of the machine. The rails 4-5 serve as tra'ck's for guiding sheaves 7-8 having a groove 9 in the peripherv thereof. One sheave is rotatahlv mounted on each end of the shaft 10 which carries the roller 2.

Figs. 2 and 3 show more clearlv the manner in which the sheave isrnounted on the shaft. The sheave 7 is positioned within a cage or block designated generally as 11. p The cage comprises spaced side members 1213 but is open on the top and bottom in order to permit insertion of the sheave within the block between the sides.

In assembling the block and sheave, the sheave 7 is placed within the block 11, and the bushing 14 is forced through correspondingly shaped apertures in the sheave and in the sides of the block. The bushing is thus fixed in the block but the sheave is rotatable upon the bushing. The interior of the bushing serves as a bearing surface for the end of the shaft 10.

The ends 15 of the cage or block connecting the side portions 12-13 are threaded to receive an adjusting bushing 16 which bushing is threaded on its interior in a direction opposite to the threaded surfaces in the ex terior of the bushing. That is, if the exterior surfaces of the bushing are provided with a right hand thread, the interior of the bushing would be provided with a left hand thread. A red 17 is provided with a thread corresponding to the thread on the interior of the bushing. A suitable look nut '18 is provided for fixing the adjusting bushing in proper position.

The threaded rod 17 is connected at one end to a sprocket chain 19 which chain is guided over two pair of sprocket gears 20 each pair being rotatablv mounted at opposite ends of the track. As shown. the sprocket gears 20 are carried on shaft 2122 supported at opposite ends of the track on suitable brackets 23. The brackets are shown as mounted on the base 1.

Preferably. each end of the sprocket chains are connected to the cage'or block housing the sheave. through an adiust'able connection comprising the adjustin bushing 16 and the threaded rod 17. Where a sprocket chain is provided. it is particularly desirable to rovide a means of adjusting the tension and length of the sprocket chain without rotation' the sprocket chain. This can be accomplished hv emploving the adjustinn bushing herein dis losed.

As shown. the traveling felt is guided over the rollers 24. the movable compensating roller 2. and rollers 25 and 26. The looping of the felt over the compensating roller 2 which mav be moved to different positions upon the rails 4-5. enables relative constant tension to be maintained in the traveling felt 3. under various changes in the length of the felt strip due to contraction and expansion.

A relative uniform tension in the felt strip 3 is maintained irrespective of the relative I position of the compensating roller 2 upon the rails 4-5. by means of a weight 27 the efi'ect of which is transmitted to the sprocket chains 19. through a drum 28 fixed on an extension of the shaft 22. The wei ht is freelv suspended on one end of a cable 29. the cable being wound around the drum 2. sufficient number of turns to provide for movement of the compensating roller 2 throughout the length of the'rails 4-5, the other'end of the cable being fixed in the. cable drum 28 as at 29. Preferably, an outer bearing 30 is provided for the extension of shaft 22 upon which the drum 28 is mounted.

The diagrammatic view in Fig. 5 indicates a condition in which the felt traveling strip has shrunk, so that the length of said felt strip is less thanthat indicated by the full line position of the compensating roller. The changed position of the compensating roller is indicated in dot and dash line position. The changed position of the compensating roller will result in'the correspondingly changed position of the weight. The changed position of the weight is also indicated in this figure by a dot and dash line position 27' of the weight. However, the tension in the felt strip will be the same for the two positions of the compensating roller.

There are occasions when it is necessary to remove the efi'ect of the weight, upon the compensating roller 2, such for example as when the felt strip is being initially installed, or when being repaired. In compensating devices heretofore employed in the prior art, it has been necessary to remove the weights from the cable in order to relieve the tension upon the compensating roller 2. As

shown, a means is provided whereby the tension upon the compensating roller 2 may be removed, without requiring the removal of the weight from the cable, and also means are provided whereby the roller 2 may be conveniently moved 'or shifted to different positions upon the pair of tracks.

As shown, a ratchet gear 31 is fixed on shaft 22 and an arm 32 having one end rotatably mounted on shaft 22 is provided; a pawl 33 is pivotally mounted on the arm 32. A

stationary locking pawl 34 may also be provided for engagement with the ratchet geaf 31 so that the arm 32 may be rec-iprocated and the stationary pawl 34 may be edective to hold the weight in any given position during one direction of movement of the arm 32. During the normal operation of the machine in which a relatively uniform tension is maintained in the traveling felt, both of the pawls 33 and 34 will be out of engagement with the ratchet gear 31.

Although'only one preferred form of the invention has been herein shown for purposes of illustration, it is understood that various changes and modifications maybe made without departing from the spirit and scope of the invention as defined in the appended claims.

What I therefore claim and desire to secure by Letters Patent is: Y

1. A paper making machine including a traveling felt of variable length due to the varying degrees of moisture to which the felt a shaft on which said sheave is rotatably mounted, a roller over which said felt is. guided, said roller being mounted on said shaft, compensator means automatically to vary the position of said sheave to maintain substantially constant felt tension. er making machine including a 2. A pap traveling felt of variable length due to the varying degrees of moisture to which the felt is subjected an automatic compensator to automatic compensator to v maintain relative constant tension in the felt during normal running conditions including a pair of tracks, a sheave having a groove in the periphery thereof guided on said tracks, a shaft on which said sheave is rotatably mounted, a roller over which said felt is guided, said roller being mounted on said shaft, compensator means automatically to vary the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connecting mechanism between the sheave and weight whereby theposition ofthe sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant tension on the felt 3. A paper making machine including a traveling felt of variable length due to the varying degrees of moisture to which the felt is subjected, an automatic compensator to maintain relative constant tension in the felt during normal running conditions including a pair of tracks, a sheave having a groove in the periphery thereof guided on said tracks, a shaft, on which said sheave is rotatably mounted, a roller over which said felt is guided, said roller being mounted on said shaft, compensator means automatically to vary the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connecting mechanism between the sheave and weight whereby the position of the sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant ten- .sion on the felt. said connecting mechanism including a shaft at one side of said sheave, a drum and cable thereon, said drum being mounted on said shaft, said weight being suspended from one end of said cable. sprockets mounted on said shaft, other sprockets rotatablv mounted on the other side of said shaft and sprocket chains passing over said sprockets and having the ends thereof connected to said sheaver 4. A paper making machine including a traveling felt of variable length due to the varying degrees of moisture to which the d estates feltis subjected, an automatic compensator to maintain relative constant tension in the felt during normal running conditions including a pair of tracks, a sheave having a goove in the periphery thereof guided on said tracks, a shaft on which said sheave is rotatably mounted, a roller over which said felt is guided, said roller being mounted on said shaft, compensator means automatically to vary the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connecting mechanism between thesheave and weight whereby the position of the sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant tension on the felt. said connecting mechanism including a shaft at one side of said sheave, a drum and cable thereon, said drum being mounted on said shaft, said weight being suspended from one end of said cable. sprockets mounted on said shaft, other sprockets rotatably mounted on the other side of said shaft and sprocket chains passing'over said sprockets and having the ends thereof connected to said sheave, and adjustable means for maintaining constant tension in the chains.

5. A paper making machine including a traveling felt of variable length due to the varying degrees of moisture to which the felt is subjected, an automatic compensator to maintain relative constant tension in the felt during normal running conditions including a pair of tracks, a sheave having a groove in the periphery thereof guided on said tracks a shaft on which said sheave is rotatably mounted, a roller over which said felt is guided, said roller being mountedon said shaft. compensator means automatically to vary ,the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connecting mechanism between the sheave and weight whereby the position of the sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant tension on the felt, said connecting mechanism mcludlnga shaft at one slde of said sheave, a drum and cable thereon, sa'id drum cage andhaving oppositely threaded portions on the interior and exterior respectively of said bushing, and a rod threaded into said bushing said rod being connected with one end of said chain.

6. A paper making machine including a traveling felt of variable length due to the Varying degrees of moisture to which the felt is subjected, an automatic compensator to maintain relative constant tension in the felt during normal running conditions including a pair of tracks, a sheave having a groove in the periphery thereof guided on said tracks, a shaft on which said sheave is rotatably mounted, a roller over which said felt is guided, said roller being mounted on said shaft. compensator means automatically to vary the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connecting mechanism between the sheave and weight whereby the position of the sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant tension on the felt, said connecting mechanism including a shaft at one side of said sheave, a drum and cable thereon, said drum being mounted on said shaft, said weight being suspended from one end of said cable,

sprockets mounted on said shaft, other sprockets rotatably mounted on the other side of said shaft and sprocket chains passing over said sprockets and having the ends thereof connected to said sheave, and adjustable means for maintaining constant tension in the chains, said means including a cage for said sheave and a bushing threaded into said cage and having oppositely threaded portions on the interior and exterior. respectively of said bushing, and a rod threaded into said bushing said rod being connected with one end of said chain, and locking means for maintaining the sheave in fixed position independent of the expansion and contraction of the felt to. facilitate repair.

7. A paper making machine including a traveling felt of variable length due to the varying degrees of moisture to which the felt is subjected, an automatic compensator to maintain relative constant tension in the felt during normal running conditions including a pair of tracks, a sheave having a groove in the periphery thereof guided on said tracks, a shaft on which said sheave is rotatably mounted. a roller over which said felt is guided, said roller being mounted on said shaft, compensator means automatically to vary the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connecting mechanism between the sheave and weight whereby the position of the sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant tension on the felt, said connecting mechanism including a. shaft at one side of said sheave, a

drum and cable thereon, said drum being mounted on said shaft, said weight being suspended from one end of said cable, sprockets mounted on said shaft, other sprockets r otatably mounted on the other side of said shaft and sprocket chains passing over said sprockets and having the ends thereof connected to said sheave, and adjustable means for maintaining constant tension in. the chains, said means including a cage for said sheave and a bushing threaded into said cage and having oppositely threaded portions on the interior and exterior respectively of said bushing, a rod threaded into said bushing said rod being connected with one end 0 said chain, and lockingmeans for mainta' the sheave in fixed position independent 0 the expansion and contraction of the felt to facilitate repair, said locking means including a ratchet wheel mounted on the shaft which supports said cable drum, and a locking pawl cooperating therewith.

8. A paper making machine including a raveling felt of variable length due to the varying degrees of moisture to which the felt is subjected an automatic compensator 'to maintain relative constant tension the vfelt during normal running conditions mcluding a pair of tracks, a sheave having a "groove in the periphery thereof guided on said tracks, a shaft on which said sheave is rotatably; mounted, a roller over which said felt is guided, said roller being mounted on said shaft, compensatormeans automatically to vary the position of said sheave to maintain substantially constant felt tension, said compensator means including a freely suspended weight and connectin mechanism between the sheave and weig t whereby the position of the sheave is moved on the track in accordance with the expansion and contraction of the felt to maintain relatively constant tension on the felt, said connectingmechanism including a shaft at one side of said sheave, a drum and cablethereon, said drum being mounted on said shaft, said weight being Suspended from one end of said cable, sprockets mounted on said shaft, other sprockets rotatably mounted on the other side of said shaft and sprocket chains passing over said sprockets and having the ends thereof connected to said sheave, and adjusta locking pawl cooperating therewith, a manuall operable arm rotatably mounted on the rate at Wheel shaft, and a pawl mounted on said arm and adapted to be moved into and out of doggin relation with said ratchet, whereby the e ect'of said weight upon said sheave may be relieved.

9. In a machine of the character described, I

apair of tracks, a pair of sheaves one on each track, each sheave having a groove in the periphery thereof adapted to fit on the track, a shaft connecting said sheaves, said sheaves being rotatabl mounted on said shaft, a cage for each of said sheaves, said cage being rotatably mounted on said shaft, a felt guidin roller mounted on said shaft between sai sheaves, compensating means for moving said sheaves on said track including sprockets mounted at the end of said tracks,

sprocket chains guided over said sprockets,

one chain being provided for each sheave,

and means for adjustably connecting the ends of the chain to the ca e.

10. In a machine of t e character described, a pair of tracks, a pair of sheaves one pn each track, each sheave having a groove in the periphery thereof adapted to fit on the track, a shaft connecting said sheaves, said sheaves being rotatably mounted on said shaft a. cage for each of said sheaves, said ca 0 mg rotatably mounted on said shaft, a elt guiding roller mounted on said shaft between said sheaves, compensating means for moving said sheaves on said track including sprockets mounted at the end of said tracks, sprocket chains guided over said sprockets, one chain being provided for each sheave, and means for adjustably connecting the ends of the chain to the cage, said means including a threaded rod connected to the end of the chain and a bushing having oppositely threaded portions on the intenor and exterior respectively of said bushing, said bushing being threaded into said cage and adapted to receive said threaded rod whereby the tension of said sprocket chain maybe adjusted by rotating said bushing and without requiring rotation of said sprocket chain. v

11. In a machine of the class described, a cage, a sprocket chain, a means for effecting an adjustable connection between the ends of said sprocket chain and said cage with-' out necessitating the rotation of said sprocket chain.

' 12. In a machine of the class described, a cage, 3. sprocket chain, a means for effecting an adjustable connection between the ends of said sprocket chain and said cage without necessitating the rotation of said sprocket chain, said means including a bushing having a right hand thread on the exterior thereof and adapted to be threaded into said cage, said bushing having a left hand thread on the interior thereof, a rod connected to one "6 emma of the chains at the end and havin a left hand thread and ada ted to be three ed into the interior of said ushing, and means on said bushing to facilitate the rotation thereof.

In testimony whereof I afliz; my signature.

WILLEAM J. TREMPE. 

